US 7508980 B2 Abstract A method for preparing stereo images by using a surveying instrument, which comprises an image pickup means for acquiring an image in a collimating direction, and a distance measuring and angle measuring means for measuring a distance and angle of a collimating point, comprising a step of measuring distances and angles on at least three collimating points by installing said surveying instrument at a known point, a step of measuring angles on the three collimating points by setting said surveying instrument at an unknown point, a step of calculating coordinates of the unknown point based on surveying data of the three collimating points, a step of acquiring images from each of the known point and the unknown point for at least one of said three collimating points, and a step of preparing stereo images from the images from the known point and the unknown point based on coordinate data of the known point, distance measurement data, and angle measurement data from the known point, and based on coordinate data and angle measurement data calculated with respect to the unknown point.
Claims(5) 1. A method for preparing stereo images by using a surveying instrument, which comprises an image pickup means for acquiring an image in a collimating direction, and a distance measuring and angle measuring means for measuring a distance and an angle of a collimating point, comprising a step of measuring distances and angles on at least three collimating points by installing said surveying instrument at a known point, a step of measuring angles on the three collimating points by installing said surveying instrument at an unknown point, a step of calculating coordinates of the unknown point based on surveying data of the three collimating points, a step of acquiring images from each of the known point and the unknown point for at least one of the three collimating points, and a step of preparing stereo images from the images from the known point and the unknown point based on coordinate data of the known point, distance measurement data, and angle measurement data from the known point, and based on coordinate data and angle measurement data calculated with respect to the unknown point.
2. A method for preparing stereo images according to
3. A method for preparing stereo images according to
4. A three-dimensional data preparation system, comprising an image pickup means for acquiring an image in a collimating direction, a distance measuring means capable to measure distance of the collimating point, an angle measuring means capable to measure an angle of the collimating point, a storage unit for storing distance measurement data, angle measurement data and the pickup image, and a control arithmetic unit, wherein said image pickup means takes images from a known point and an unknown point with respect to at least one collimating point among at least three collimating points, said control arithmetic unit calculates coordinate data of the unknown point based on coordinate data of the known point, distance measurement data and angle measurement data of at least three collimating points from the known point, and angle measurement data of said three collimating points from the unknown point, and prepares stereo images from the images based on the coordinate data, the distance measurement data, and the angle measurement data of the known point, and the calculated coordinate data and the angle measurement data of the unknown point.
5. A three-dimensional data preparation system according to
Description The present invention relates to a method for preparing stereo images by taking images of an object at least from two directions and for preparing stereo images from a plurality of images thus taken. The present invention also relates to a system for preparing 3-demensional data based on a stereo image by associating the stereo image with measured data. A stereo image is an image to represent an object stereoscopically, and the stereo image is an image acquired through image pickup of the same object by changing image pickup directions. By associating points on respective images with each other, it is possible to obtain 3-dimensional data of points, which constitute the image. For the purpose of obtaining 3-dimensional data from a stereo image, it is necessary to perform matching of two images (stereo-matching), and conditions to enable to perform stereo matching (external orientation elements) are required. As the external orientation elements, 3-dimensional data, image pickup directions, tiltings, magnifications, etc. of two image pickup points (camera positions) are respectively required. In order to perform stereo matching of two images, it is necessary to have relative rotation of left and right cameras with respect to a base line vector between the left and right cameras, i.e. relative orientation elements. The relative orientation elements are calculated based on the external orientation elements. In the past, when a stereo image is to be prepared, images of an object are taken by a camera from two known points respectively, and external orientation elements necessary for calculating relative orientation elements are obtained. For this reason, it is necessary to set reference points on the object, to separately measure the reference points by a total station or the like, and to find positions and tiltings of the cameras based on 3-demensional position information of the reference points. In this respect, it is necessary to perform photogrammetry to obtain a stereo image, to set reference points (pass points) in the image after photogrammetry, and to perform measurement on the reference points by a surveying instrument such as a total station from two known points where images have been taken respectively. Moreover, six or more pass points are required, for instance, and this leads to complicated measuring operation. It is an object of the present invention to simplify relative orientation operation, to facilitate association for preparation of a stereo image and to simplify 3-dimensional measurement operation based on the stereo image. To attain the obtain object, the present invention provides a method for preparing stereo images by using a surveying instrument, which comprises an image pickup means for acquiring an image in a collimating direction, and a distance measuring and angle measuring means for measuring a distance and an angle of a collimating point, comprising a step of measuring distances and angles on at least three collimating points by installing the surveying instrument at a known point, a step of measuring angles on the three collimating points by installing the surveying instrument at an unknown point, a step of calculating coordinates of the unknown point based on surveying data of the three collimating points, a step of acquiring images from each of the known point and the unknown point for at least one of the three collimating points, and a step of preparing stereo images from the images from the known point and the unknown point based on coordinate data of the known point, distance measurement data, and angle measurement data from the known point, and based on coordinate data and angle measurement data calculated with respect to the unknown point. Also, the present invention provides the method for preparing stereo images as described above, wherein at least three collimating points can be collimated from the known point and the unknown point, and, in the images acquired from the known point and the unknown point, collimating points from the known point and the unknown point are made correspond with each other based on deviation on the image. Further, the present invention provides the method for preparing stereo images as described above, wherein the method further comprises a step of acquiring images of all collimating points from the known point and the unknown point, and a step of making the collimating points of the images correspond with the collimating points of the image obtained at the known point respectively. The present invention provides a three-dimensional data preparation system, which comprises an image pickup means for acquiring an image in a collimating direction, a distance measuring means capable to measure distance of the collimating point, an angle measuring means capable to measure an angle of the collimating point, a storage unit for storing distance measurement data, angle measurement data and the pickup image, and a control arithmetic unit, wherein the image pickup means takes images from a known point and an unknown point with respect to at least one collimating point among at least three collimating points, the control arithmetic unit calculates coordinate data of the unknown point based on coordinate data of the known point, distance measurement data and angle measurement data of at least three collimating points from the known point, and angle measurement data of the three collimating points from the unknown point, and prepares stereo images from the images based on the coordinate data, the distance measurement data, and the angle measurement data of the known point, and the calculated coordinate data and the angle measurement data of the unknown point. Also, the present invention provides the three-dimensional data preparation system as described above, wherein the two stereo images are associated with each other based on the coordinate data of the known point, the distance measurement data and the angle measurement data of at least three collimating points from the known point and the coordinate data of the unknown point and the angle measurement data from the unknown point, and 3-dimensional data is a calculated from the images thus associated. According to the present invention, in a method for preparing stereo images by using a surveying instrument which comprises an image pickup means for acquiring an image in a collimating direction, and a distance measuring and angle measuring means for measuring a distance and an angle of a collimating point, the method comprises a step of measuring distances and angles on at least three collimating points by installing the surveying instrument at a known point, a step of measuring angles on the three collimating points by installing the surveying instrument at an unknown point, a step of calculating coordinates of the unknown point based on surveying data of the three collimating points, a step of acquiring images from each of the known point and the unknown point for at least one of the three collimating points and, a step of preparing stereo images from the images from the known point and the unknown point based on coordinate data of the known point, distance measurement data, and angle measurement data from the known point, and based on coordinate data and angle measurement data calculated with respect to the unknown point. As a result, there is no need to perform photogrammetry and surveying of pass points, and this extensively simplifies the preparation of stereo images. Further, according to the present invention, a three-dimensional data preparation system comprises an image pickup means for acquiring an image in a collimating direction, a distance measuring means capable to measure distance of the collimating point, an angle measuring means capable to measure an angle of the collimating point, a storage unit for storing distance measurement data, angle measurement data and the pickup image, and a control arithmetic unit, the image pickup means takes images from a known point and an unknown point with respect to at least one collimating point among at least three collimating points, the control arithmetic unit calculates coordinate data of the unknown point based on coordinate data of the known point, distance measurement data and angle measurement data of at least three collimating points from the known point, and angle measurement data of the three collimating points from the unknown point, and prepares stereo images from the images based on the coordinate data, the distance measurement data, and the angle measurement data of the known point, and the calculated coordinate data and the angle measurement data of the unknown point. Thus, there is no need to have a device required for photogrammetry and a surveying instrument such as a total station. Measuring operation can be carried out by using a single system, and surveying operation can be extremely simplified. Description will be given below on the best mode for carrying out the invention referring to the drawings. First, description will be given on general features of a surveying instrument The main unit The frame unit Referring to The frame unit In the storage unit Now, description will be given on a method for preparing a stereo image and a method for preparing 3-dimensional data by using the surveying instrument, referring to The surveying instrument Next, by the surveying instrument The surveying instrument As seen in The control arithmetic unit A position and tilting of the surveying instrument (image pickup unit), i.e. external orientation elements of the left and right images, are read from the storage unit The left and right images are rearranged based on the relative orientation elements, and left and right stereo images are prepared respectively (Step Further, corresponding points are extracted, and matching of the stereo images (matching of the left and right stereo images) is performed (Step The stereo image after matching contains 3-dimensional data on the image. For instance, by designating a pixel on the screen, it is possible to obtain 3-dimensional data to correspond the pixel (Step Further, based on relation between the coordinate data already known on the image, e.g. the 3-dimensional data of the collimating point P Next, by referring to Images are taken on the points P As described above, distance measurement and angle measurement are performed on the points P Next, distance measurement and angle measurement are performed on the points P External orientation elements of the images taken from the points B and C are obtained. Further, from the external orientation elements of the two images, relative orientation elements can be calculated. As a result, it is possible to associate the stereo images with each other and to prepare 3-dimensional data. As described above, if a first survey point, i.e. the point A, is set by a surveying instrument with the image pickup unit as a known point, subsequent unknown points can be sequentially turned to known points from at least three points, and it is possible to prepare a stereo image and to prepare 3-dimensional data in wide range. Patent Citations
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